Battery, electronic device, electric vehicle, electrical storage device, electrical storage system and wearable terminal

ABSTRACT

A battery is provided including a battery cell having main top and bottom surfaces, and a plurality of side surfaces; and at least one resin section including a cured resin that covers at least three of the plurality of side surfaces of the battery cell, but that does not cover substantially all of the top and bottom surfaces of the battery cell.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority PatentApplication JP 2014-047390 filed in the Japan Patent Office on Mar. 11,2014, and Japanese Priority Patent Application JP 2014-211971 filed inthe Japan Patent Office on Oct. 16, 2014, the entire content of which ishereby incorporated by reference.

BACKGROUND

The present disclosure relates to a battery, an electronic device, anelectric vehicle, an electrical storage device, an electrical storagesystem and a wearable terminal.

Recently, portable electronic apparatuses such as a note-type personalcomputer (PC) and a cellular phone apparatus have become widespread, anda lithium ion secondary battery, which has advantages of high voltage,high energy density, and reduction in size, has been used as a powersupply of such portable electronic apparatuses.

The lithium ion secondary battery has been used widely as a battery packin which a circuit such as a protective circuit is applied to a batterycell in which a battery element is packaged with an exterior laminatefilm. As battery pack-related technologies, technologies disclosed inJapanese Unexamined Patent Application Publication Nos. 2008-300245,2004-335387, 2013-152935, 2011-003294, and 2009-181802 have beensuggested.

SUMMARY

In the battery pack, it is demanded to increase the energy density pervolume.

Accordingly, it is desirable to provide a battery pack capable ofincreasing an energy density per volume, and an electronic apparatus anda wearable terminal which use the battery pack.

In an embodiment, a battery is provided including a battery cell havingmain top and bottom surfaces, and a plurality of side surfaces; and atleast one resin section including a cured resin that covers at leastthree of the plurality of side surfaces of the battery cell, but thatdoes not cover substantially all of the top and bottom surfaces of thebattery cell.

In another embodiment, a battery includes a battery cell having main topand bottom surfaces, a plurality of side surfaces, and a plurality ofcorners. The battery also includes at least one resin section includinga cured resin that covers portions of at least two corners of thebattery cell, but that does not cover substantially all of the top andbottom surfaces of the battery cell.

In another embodiment, a battery includes a battery cell having aplurality of side surfaces and at least one curved surface connectingthe side surfaces, and at least one resin section that covers the sidesurfaces of the battery cell, but that does not cover at leastsubstantially all of the curved surface of the battery cell. Accordingto an embodiment of the present disclosure, there is provided a batterypack including a battery cell, a substrate section that is connected tothe battery cell, and one or more resin sections which include a curedmaterial of a curable resin composition sheet, and which come into closecontact with a close contact portion including at least a part of thebattery cell, or at least a part of the battery cell and at least a partof the substrate section. The curable resin composition sheet is athermosetting resin composition sheet or an energy beam curable resincomposition sheet.

According to other embodiments of the present disclosure, there areprovided an electronic apparatus and a wearable terminal which includethe battery pack.

According to the present disclosure, it is possible to increase theenergy density per volume.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exploded perspective view illustrating a configurationexample of a battery pack according to a first embodiment of the presentdisclosure;

FIG. 2 is a perspective view illustrating an external appearance of thebattery pack according to the first embodiment of the presentdisclosure;

FIG. 3A is a perspective view illustrating an external appearance of thebattery cell, and FIG. 3B is an exploded perspective view illustrating aconfiguration example of the battery cell;

FIG. 4A is a partial cross-sectional view of the battery pack, and FIG.4B is a partial cross-sectional view of the battery pack;

FIG. 5 is a partial cross-sectional view of the battery pack;

FIG. 6 is an exploded perspective view illustrating a configurationexample of a typical battery pack;

FIG. 7A is a perspective view in which a part of the typical batterypack is omitted, and FIG. 7B is a perspective view in which a part ofthe battery pack according to the first embodiment of the presentdisclosure is omitted;

FIG. 8A is a schematic cross-sectional view illustrating a regionsurrounded by dotted lines when viewed from a direction of an arrowVIIIA in FIG. 7A, and FIG. 8B is a schematic cross-sectional viewillustrating a region surrounded by dotted lines when viewed from adirection of an arrow VIIIB in FIG. 7B;

FIG. 9A is a schematic view illustrating a region surrounded by dottedlines when viewed from a direction of an arrow Q1 in FIG. 7A, and FIG.9B is a schematic view illustrating a region surrounded by dotted lineswhen viewed from a direction of an arrow Q2 in FIG. 7B;

FIG. 10 is an exploded perspective view of a battery pack using a tape;

FIG. 11A is a cross-sectional view of the battery pack using the tape,and FIG. 11B is a cross-sectional view of a battery pack to which athermosetting resin composition sheet of the present disclosure isapplied;

FIG. 12 is an exploded perspective view illustrating a configurationexample of a modification example of the battery pack;

FIG. 13A is an exploded perspective view illustrating a configurationexample of a battery pack of Modification Example 3, and FIG. 13B is anexploded perspective view illustrating the configuration example of thebattery pack of Modification Example 3;

FIG. 14A is a perspective view illustrating the external appearance ofthe battery pack of Modification Example 3, and FIG. 14B is aperspective view illustrating the external appearance of the batterypack of Modification Example 3;

FIG. 15 is a schematic view illustrating an example of an electricalstorage system for a house to which the present disclosure is applied;

FIG. 16 is a schematic view schematically illustrating an example of aconfiguration of a hybrid car employing a series hybrid system to whichthe present disclosure is applied;

FIG. 17 is a perspective view illustrating an example of externalappearance of a wearable apparatus in which a battery pack is embedded;and

FIG. 18 is a block diagram illustrating an example of a configuration ofa wearable terminal.

DETAILED DESCRIPTION

Embodiments of the present application will be described below in detailwith reference to the drawings.

Summary of Present Disclosure

Summary of the present disclosure will be described for easyunderstanding of the present disclosure. Typical battery packs (refer toJapanese Unexamined Patent Application Publication Nos. 2008-300245,2004-335387, 2013-152935, 2011-003294, and 2009-181802) can be largelyclassified into a battery pack to which an accommodation member isapplied, a battery pack to which resin molding is applied, and a batterypack to which the accommodation member and the resin molding areapplied.

The battery pack to which the accommodation member is applied is abattery pack in which a battery cell and a protective circuit substrateare accommodated in an accommodation member such as a holder and arefixed therein (Japanese Unexamined Patent Application Publication No.2013-152935).

The battery pack to which the resin molding is applied is a battery packin which at least a part of the battery cell, the protective circuitsubstrate, and the like is covered with a resin by the resin molding,and these components are integrated with each other (Japanese UnexaminedPatent Application Publication Nos. 2004-335387, 2011-003294, and2009-181802).

The battery pack to which the resin molding and the accommodation memberare applied is a battery pack in which the battery cell, the protectivecircuit substrate, and the like are accommodated in the accommodationmember such as the holder, and the resin molding and the like areperformed, whereby a resin, the battery cell, the protective circuitsubstrate, and the like are integrated with the accommodation member(Japanese Unexamined Patent Application Publication No. 2008-300245).

The typical battery packs have the following problems. In the batterypack to which the resin molding is applied, and the battery pack towhich the resin molding and the accommodation member are applied, thereis a concern that insulation properties of an intended site may beunstable due to a variation in molding conditions. In the battery packto which the resin molding is applied, and the battery pack to which theresin molding and the accommodation member are applied, facilityinvestment increases, and thus it is difficult to prepare the batterypacks at low cost. In the battery pack to which the resin molding isapplied, there is a concern that strength may be unstable due tovariation in molding conditions. In the battery pack to which the resinmolding is applied, and the battery pack to which the resin molding andthe accommodation member are applied, there is a concern thatdimensional accuracy may be unstable due to variation in moldingconditions. In the battery pack to which the accommodation member isapplied, there is a trade-off limit between large capacity andsecurement of strength. In the battery pack to which the resin moldingis applied, there is a problem in that a production process depends on amolding cycle. In the battery pack to which the resin molding isapplied, a large dimensional tolerance of the battery cell has an effecton a quality thereof In the battery pack to which the resin molding isapplied, design restriction conditions become strict.

The present inventors have made a thorough investigation inconsideration of the above-described problems in typical battery packs,and as a result, they have found that in a case where the followingcharacteristics of a curable resin composition sheet are utilized andthe characteristics are used for exterior packaging of the battery cellor member fixing, this case is effective for solving the above-describedproblems. In addition, in this specification, the curable resincomposition represents a thermosetting resin composition or an energybeam curable resin composition.

The curable resin composition sheet can be easily processed into a shapeconforming to a portion to which the curable resin composition sheetadheres. Temporary adhesion of the curable resin composition sheet canbe simply performed by sticking the curable resin composition sheet witha low pressure, and thus the curable resin composition sheet canreliably adhere to a site at which strength performance is desired to besecured. In addition, the thermosetting resin composition sheet can bemelted only when being left as is in a constant temperature environmentafter adhesion, and then can be cured. The curable resin compositionafter curing has appropriate hardness, and is not easily peeled off froman adhering portion. On the other hand, the curable resin compositionafter curing may be adjusted to have appropriate flexibility byperforming component adjustment or adjustment of curing conditions(heating conditions, irradiation time, and the like).

In the battery pack according to an embodiment of the present disclosureto which the curable resin composition sheet having the characteristicsis applied, it is possible to solve the above-described problems asdescribed below.

In the battery pack according to the embodiment of the presentdisclosure, a molding process is not necessary, and thus a necessaryamount of a curable resin composition sheet can be integrated with anecessary site of the battery cell in the same manner as a label.Accordingly, it is possible to suppress insulation properties of anintended site from becoming unstable due to a variation in moldingconditions.

In the battery pack according to the embodiment of the presentdisclosure, the battery pack is prepared by a process of sticking thecurable resin composition sheet in the same manner as a label, andcuring the curable resin composition sheet, and thus the facility forproducing a typical battery pack is applicable. Accordingly, it ispossible to suppress an increase in facility investment for preparationof the battery pack according to the embodiment of the presentdisclosure.

It is easy to obtain a desired curable resin composition sheet byprocessing the curable resin composition into a sheet shape.Accordingly, differently from the battery pack to which the resinmolding is applied, in the battery pack according to the embodiment ofthe present disclosure, strength failure due to molding conditions doesnot occur.

The battery pack according to the embodiment of the present disclosurehas a structure in which the curable resin composition processed to havea sheet shape is integrated with a battery cell, and thus it is possibleto raise a design limit value based on an increase in capacity andsecurement of strength, and thus it is possible to further improve thecapacity and the strength.

A process of producing a battery pack according to the embodiment of thepresent disclosure does not include a molding process. According tothis, in the battery pack according to the embodiment of the presentdisclosure, a problem caused by the molding process does not occur. Inaddition, with regard to the battery pack to which the resin molding isapplied, restrictions on design and manufacturing due to a largedimensional tolerance of the battery cell can be solved by removing themolding process by using the curable resin composition sheet.

Hereinafter, embodiments of the present disclosure will be describedwith reference to the attached drawings. In addition, description willbe given in the following order.

1. First Embodiment (First Example of Battery Pack)

2. Second Embodiment (Second Example of Battery Pack)

3. Third Embodiment (Example of Electrical Storage System, and the like)

4. Other Embodiments (Modification Examples)

In addition, embodiments and the like to be described below areappropriate specific examples of the present disclosure, and thecontents of the present disclosure are not limited to the embodimentsand the like. In addition, effects described in this specification areillustrative only, and it is not intended to deny presence of effectsdifferent from the illustrated effect.

1. First Embodiment

A configuration example of a battery pack according to a firstembodiment of the present disclosure will be described. FIG. 1 is anexploded perspective view illustrating a configuration example of thebattery pack according to the first embodiment of the presentdisclosure. FIG. 2 is a perspective view illustrating externalappearance of the battery pack according to the first embodiment of thepresent disclosure.

As illustrated in FIGS. 1 and 2, the battery pack according to the firstembodiment of the present disclosure includes a battery cell 11, resinsections 12 a and 12 b, and a substrate section 13. The resin section 12a is obtained when a curable resin composition sheet 12 a′ is cured. Theresin section 12 b is obtained when a curable resin composition sheet 12b′ is cured.

In addition, in the following description, in a case where the resinsection 12 a and the resin section 12 b are not discriminated, the resinsections 12 a and 12 b will be collectively described as a resin section12. The battery pack according to the first embodiment of the presentdisclosure includes one or more resin sections 12. Similarly, in a casewhere the curable resin composition sheet 12 a′ and the curable resincomposition sheet 12 b′ are not discriminated, the curable resincomposition sheets 12 a′ and 12 b′ are collectively described as acurable resin composition sheet 12′. In FIG. 1, the curable resincomposition sheet 12′ having a shape before curing of the resin section12 illustrated in FIG. 2 is illustrated.

A lead 21 a and a lead 21 b of the battery cell 11 are connected to thesubstrate section 13. In addition, the resin section 12 a comes intoclose contact with a close contact portion including at least a part ofthe battery cell 11 and at least a part of the substrate section 13, andthe resin section 12 b comes into close contact with a close contactportion including at least a part of the battery cell 11, therebyobtaining a battery pack having the external appearance illustrated inFIG. 2.

Hereinafter, details of the configuration of the battery pack will bedescribed.

Battery Cell

Typical examples of the battery cell 11 include a laminated film typesecondary battery and the like. Examples of the secondary batteryinclude a nonaqueous electrolyte secondary battery such as a lithium ionsecondary battery, and the like. In the present disclosure, the lithiumion secondary battery also includes a secondary battery in which Lisegregates at a negative electrode during charging similar to a casewhere for example, a lithium metal is used for the negative electrode.In addition, the battery cell 11 may be constituted by a secondarybattery other than the lithium ion secondary battery. In the followingdescription, description will be given to an example in which thebattery cell 11 is constituted by a laminated film type lithium ionsecondary battery.

As illustrated in FIGS. 3A and 3B, the battery cell 11 includes abattery element 20, an exterior material 27 that packages the batteryelement 20, leads 21 a and 21 b which are connected to the batteryelement 20, and adhesive films 24 and 25. The lead 21 a is a positiveelectrode side lead that is connected to, for example, a positiveelectrode. The lead 21 b is a negative electrode side lead that isconnected to, for example, a negative electrode.

As illustrated in FIG. 3B, after the battery element 20 is accommodatedin an accommodation portion 26 provided to the exterior material 27,three sides except for a side that is folded back are sealed withthermal fusion and the like. The adhesive film 24 is provided betweenthe lead 21 a and the exterior material 27, and the exterior material 27and the lead 21 a are fused to each other through the adhesive film 24.Similarly, the adhesive film 25 is provided between the lead 21 b andthe exterior material 27, and the exterior material 27 and the lead 21 bare fused to each other through the adhesive film 25. In this manner,the battery cell 11 having the external appearance illustrated in FIG.3A is obtained. In addition, a member having a shape in which thebattery element 20 is accommodated in the exterior material 27 and isnot connected to the substrate section 13 is referred to as the batterycell 11.

Battery Element

The battery element 20 includes a positive electrode, a negativeelectrode, and a separator and/or an electrolyte which are disposedbetween the positive electrode and the negative electrode. For example,the electrolyte is an electrolyte in which an electrolytic solution isretained by a polymer compound, and the like, and examples thereofinclude a gel-shaped electrolyte.

A shape of the battery element 20 is, for example, a flat shape and thelike. For example, the battery element 20 has a structure in which astrip-shaped positive electrode and a strip-shaped negative electrodeare laminated through the electrolyte and/or separator, and are wound ina longitudinal direction. The lead 21 a and the lead 21 b are connectedto the positive electrode and the negative electrode, respectively. Inaddition, in the case of using an electrolytic solution, which is aliquid electrolyte, as the electrolyte, the electrolyte is notlaminated, the battery element 20 is impregnated in an electrolyticsolution filled inside the exterior material 27. However, the batteryelement 20 may have a structure in which electrodes are laminated.Examples of the battery element 20 include a battery element having astructure in which the positive electrode and the negative electrode arelaminated through a sheet of separator, a battery element having astructure in which the positive electrode and the negative electrode arelaminated through a sheet of strip-shaped separator that is folded in azigzag shape, a battery element having a structure in which the positiveelectrode and the negative electrode are laminated through a pair ofseparators which are folded in a zigzag shape with the negativeelectrode interposed therebetween, and the like.

For example, the positive electrode includes a positive electrodecurrent collector having a strip shape and the like, and a positiveelectrode active material layer formed on the positive electrode currentcollector. For example, the positive electrode active material layer isformed on both main surfaces of the positive electrode currentcollector. In addition, the positive electrode may have a region inwhich the positive electrode active material layer is formed only on aone-side main surface of the positive electrode current collector.

For example, the negative electrode includes a negative electrodecurrent collector having a strip shape and the like, and a negativeelectrode active material layer that is formed on the negative electrodecurrent collector. For example, the negative electrode active materiallayer is formed on both main surfaces of the negative electrode currentcollector. In addition, the negative electrode may have a region inwhich the negative electrode active material layer is formed only on aone-side main surface of the negative electrode current collector.

The lead 21 a and the lead 21 b are connected to the positive electrodecurrent collector and the negative electrode current collector,respectively.

As materials of the positive electrode active material, the negativeelectrode active material, the electrolyte, and the separator, materialsthat have been suggested already may be used, and are selected inaccordance with the type of the battery. Hereinafter, an example ofmaterials of respective components in a case where the type of thebattery is a lithium ion secondary battery that is a nonaqueouselectrolyte battery will be described.

For example, the positive electrode current collector is constituted bymetal foil such as aluminum foil. The positive electrode active materiallayer contains one or more kinds of positive electrode materials capableof intercalating and deintercalating lithium ions as a positiveelectrode active material. The positive electrode active material layermay contain other materials such as a binding agent and a conductiveagent as necessary.

Appropriate examples of the positive electrode material, which iscapable of intercalating and deintercalating lithium ions, includelithium-containing compounds such as lithium oxide, lithium phosphorousoxide, lithium sulfide, and an inter-layer compound containing lithium,and two or more kinds thereof may be mixed and used. So as to increaseenergy density, lithium-containing compounds including lithium, atransition metal element, and oxygen (O) are preferable. Examples ofthese lithium-containing compounds include lithium composite oxidehaving a layered rock salt-type structure, lithium composite phosphatehaving an olivine type structure, and the like. As thelithium-containing compounds, compounds containing at least one kind ofelement selected from the group including cobalt (Co), nickel (Ni),manganese (Mn), and iron (Fe) as a transition metal element are morepreferable.

As the lithium-containing compounds, a lithium-containing compoundexpressed as Li_(x)M1O₂ or Li_(y)M2PO₄ may be used. In the formulae, M1and M2 represent one or more kinds of transition metal elements. Valuesof x and y are different in accordance with a charging and dischargingstate of the battery, and typically satisfy relationships of 0.05≦x≦1.10and 0.05≦y≦1.10. Examples of the composite oxide that contains lithiumand a transition metal element include lithium cobalt composite oxide(Li_(x)CoO₂), lithium nickel composite oxide (Li_(x)NiO₂), lithiumnickel cobalt composite oxide (Li_(x)Ni_(1−z)Co_(z)O₂ (0<z<1)), lithiumnickel cobalt manganese composite oxide(Li_(x)Ni_((1−v−w))Co_(v)Mn_(w)O₂ (0<v+w<1, v>0, w>0)), lithiummanganese composite oxide (LiMn₂O₄) or lithium manganese nickelcomposite oxide (LiMn_(2−t)Ni_(t)O₄ (0<t<2)) which has a spinel-typestructure, and the like. Among these, a composite oxide that containscobalt is preferable. This is because high capacity is obtained andexcellent cycle characteristics are also obtained. In addition, examplesof a phosphate compound including lithium and a transition metal elementinclude a lithium iron phosphate compound (LiFePO₄), a lithium ironmanganese phosphate compound (LiFe_(1−u)Mn_(u)PO₄ (0<u<1)), and thelike. Specific examples of the lithium composite oxide include lithiumcobaltate (LiCoO₂), lithium nickelate (LiNiO₂), lithium manganate(LiMn₂O₄), and the like. In addition, a solid solution in which a partof the transition metal elements is substituted with a different elementmay be used. For example, nickel cobalt composite lithium oxide(LiNi_(0.5)Co_(0.5)O₂, LiNi_(0.8)Co_(0.2)O₂, and the like) may beexemplified.

Furthermore, from the viewpoints of obtaining relatively high electrodefilling properties and cycle characteristics, composite particles, inwhich a surface of a core particle formed from any one of theabove-described lithium-containing compounds is coated with fineparticles formed from any one of other lithium-containing compounds, maybe used.

In addition, examples of the positive electrode material capable ofintercalating and deintercalating lithium ions include oxide, disulfide,chalcogenide, a conductive polymer, and the like. Examples of the oxideinclude vanadium oxide (V₂O₅), titanium dioxide (TiO₂), manganesedioxide (MnO₂), and the like. Examples of the disulfide include irondisulfide (FeS₂), titanium disulfide (TiS₂), molybdenum disulfide(MoS₂), and the like. As the chalcogenide, a layered compound or aspinel type compound is particularly preferable, and examples thereofinclude niobium selenide (NbSe₂) and the like. Examples of theconductive polymer include sulfur, polyaniline, polythiophene,polyacetylene, polypyrrole, and the like. The positive electrodematerial may be another material other than the above-describedmaterials. In addition, two or more kinds of the above-describedpositive electrode materials may be mixed in an arbitrary combination.

In addition, as the conducting agent, for example, a carbon materialsuch as carbon black and graphite is used. Examples of the binding agentinclude at least one kind selected from resin materials such aspolyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE),polyacrylonitrile (PAN), styrene butadiene rubber (SBR), andcarboxymethyl cellulose (CMC), and copolymers containing these resinmaterials as a main component.

Negative Electrode

For example, the negative electrode current collector is constituted bymetal foil such as copper foil.

The negative electrode active material layer contains any one or morekinds of negative electrode materials capable of intercalating anddeintercalating lithium ions as the negative electrode active material,and may contain other materials, for example, the same conductive agentand the same binding agent as in the positive electrode active materiallayer as necessary.

In addition, in the nonaqueous electrolyte battery, an electrochemicalequivalent of the negative electrode material capable of intercalatingand deintercalating lithium ions is larger than that of the positiveelectrode, and is theoretically set in order for a lithium metal not toprecipitate to the negative electrode during charging.

Examples of the negative electrode material capable of intercalating anddeintercalating lithium ions include carbon materials such as anon-graphitization carbon, easy-graphitization carbon, graphite,pyrolytic carbons, cokes, glassy carbons, a fired substance of anorganic polymer compound, carbon fiber, and activated charcoal. Amongthese, examples of the cokes include pitch coke, needle coke, petroleumcoke, and the like. The fired substance of the organic polymer compoundrepresents a carbonized substance that is obtained by firing polymermaterial such as a phenol resin or a furan resin at an appropriatetemperature, and may be classified into non-graphitization carbon oreasy-graphitization carbon in some parts. These carbon materials arepreferable because a change in the crystal structure, which occursduring charging and discharging, is very small, a high charging anddischarging capacity can be obtained, and satisfactory cyclecharacteristics can be obtained. Particularly, graphite is preferablebecause an electrochemical equivalent is large and a high energy densitycan be obtained. In addition, the non-graphitization carbon ispreferable because excellent cycle characteristics are obtained.Furthermore, a material of which charge and discharge electric potentialis low, specifically, a material of which charge and discharge electricpotential is close to that of a lithium metal is preferable because highenergy density of the battery can be easily realized.

Examples of the negative electrode material capable of intercalating anddeintercalating lithium ions include a material which is capable ofintercalating and deintercalating lithium ions and includes at least onekind of a metal element and a metalloid element as a constituentelement. This is because a high energy density can be obtained when thismaterial is used. Particularly, it is more preferable to use thismaterial in combination with a carbon material because a high energydensity and excellent cycle characteristics can be obtained. Thenegative electrode material may be an elementary substance of the metalelement or the metalloid element, an alloy thereof, or a compoundthereof, and the negative electrode material may have one or more kindsof phases thereof at least at a part. In addition, in the presentdisclosure, in addition to an alloy of two or more kinds of metalelements, the term “alloy” also includes an alloy containing one or morekinds of metal elements and one or more kinds of metalloid elements. Inaddition, the alloy may contain a nonmetal element. The texture of thealloy includes a solid solution, a eutectic crystal (a eutecticmixture), an intermetallic compound, and a texture in which two or morekinds of these textures coexist.

Examples of the metal elements or the metalloid elements, whichconstitute the negative electrode material, include a metal element or ametalloid element which is capable of forming an alloy with lithium. Inaddition, the negative electrode material that contains the elementcapable of forming an alloy with lithium is referred to as analloy-based negative electrode material. Specific examples of the metalelements or the metalloid elements, which are capable of forming analloy with lithium, include magnesium (Mg), boron (B), aluminum (Al),titanium (Ti), gallium (Ga), indium (In), silicon (Si), germanium (Ge),tin (Sn), lead (Pb), bismuth (Bi), cadmium (Cd), silver (Ag), zinc (Zn),hafnium (Hf), zirconium (Zr), yttrium (Y), palladium (Pd), platinum(Pt), and the like. These may be crystalline materials or amorphousmaterials.

As the negative electrode material, for example, materials containing ametal element or a metalloid element of group 4B in a short-period typeperiodic table as a constituent element are preferable, materialscontaining at least one of silicon (Si) and tin (Sn) as a constituentelement are more preferable, and materials containing at least siliconare still more preferable. This is because silicon (Si) and tin (Sn)have a large capacity for intercalating and deintercalating lithium ionsand can obtain a high energy density. Examples of the negative electrodematerial, which contains at least one kind of silicon and tin, includeelementary silicon, alloys or compounds of silicon, elementary tin,alloys or compounds of tin, and materials that have one or more kinds ofphases thereof at least at a part.

Examples of alloys of silicon include alloys containing at least onekind selected from the group including tin (Sn), nickel (Ni), copper(Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In),silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb),and chromium (Cr) as a secondary constituent element other than silicon.Examples of alloys of tin include alloys containing at least one kindselected from the group including silicon (Si), nickel (Ni), copper(Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In),silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb),and chromium (Cr) as a secondary constituent element other than tin(Sn).

Examples of compounds of tin (Sn) or silicon (Si) include compoundscontaining oxygen (O) or carbon (C). Furthermore, the tin or siliconcompounds may contain the above-described secondary constituent elementin addition to tin (Sn) or silicon (Si).

Among these, as the negative electrode material, a SnCoC-containingmaterial, which contains cobalt (Co), tin (Sn), and carbon (C) as aconstituent element, and in which the amount of carbon is 9.9 mass % to29.7 mass %, and a ratio of cobalt (Co) on the basis of the sum of tin(Sn) and cobalt (Co) is 30 mass % to 70 mass %, is preferable. This isbecause a high energy density and excellent cycle characteristics can beobtained in this compositional range.

The SnCoC-containing material may further contain another constituentelement as necessary. As another constituent element, for example,silicon (Si), iron (Fe), nickel (Ni), chrome (Cr), indium (In), niobium(Nb), germanium (Ge), titanium (Ti), molybdenum (Mo), aluminum (Al),phosphorus (P), gallium (Ga), or bismuth (Bi) is preferable, and theSnCoC-containing material may contain two or more kinds of theseconstituent elements. This is because the capacity or cyclecharacteristics may be further improved.

In addition, the SnCoC-containing material has a phase including tin(Sn), cobalt (Co), and carbon (C), and it is preferable that this phasehave a low crystalline or amorphous structure. In addition, in theSnCoC-containing material, it is preferable that at least a part ofcarbon (C) present as a constituent element be bonded to a metal elementor a metalloid element present as another constituent element. Thereason for the preference is as follows. A decrease in the cyclecharacteristics is considered to be due to aggregation orcrystallization of tin (Sn) or the like, but when carbon (C) is bondedto another element, the aggregation or crystallization can besuppressed.

Examples of a measurement method of examining a bonding state ofelements include X-ray photoelectron spectroscopy (XPS). In XPS, in thecase of graphite, a peak of the 1s orbital (C1s) of carbon is shown at284.5 eV in a device subjected to energy calibration in order for a peakof the 4f orbital (Au4f) of a gold atom to be obtained at 84.0 eV. Inaddition, in the case of surface-contaminated carbon, the peak is shownat 284.8 eV. On the other hand, in a case where a charge density of thecarbon element increases, for example, in a case where carbon is bondedto a metal element or a metalloid element, the C1s peak is shown in arange below 284.5 eV. That is, in a case where a peak of a syntheticwave of C1s, which is obtained for the SnCoC-containing material, isshown at a range below 284.5 eV, at least a part of the carbon containedin the SnCoC-containing material enters a state of being bonded to themetal element or the metalloid element present as another constituentelement.

In addition, in the XPS measurement, for example, the C1s peak is usedfor calibration of an energy axis of a spectrum. Typically,surface-contaminated carbon is present at the surface of theSnCoC-containing material, and thus the C1s peak of thesurface-contaminated carbon is set to 284.8 eV, and this is used as anenergy reference. In the XPS measurement, a waveform of the C1s peak isobtained as a waveform that includes both the peak of thesurface-contaminated carbon and the peak of the carbon in theSnCoC-containing material. Therefore, the peak of thesurface-contaminated carbon and the peak of the carbon in theSnCoC-containing material are separated from each other, for example, byan analysis conducted using commercially available software. In thewaveform analysis, the position of a main peak present on a minimumbinding energy side is used as the energy reference (284.8 eV).

Furthermore, examples of the negative electrode material, which iscapable of intercalating and deintercalating lithium ions, furtherinclude metal oxides and polymer compounds which are capable ofintercalating and deintercalating lithium ions. Examples of the metallicoxides include oxides such as lithium titanate (Li₄Ti₅O₁₂), iron oxide,ruthenium oxide, and molybdenum oxide. Examples of the polymer materialsinclude polyacetylene, polyaniline, polypyrrole, and the like.

In addition, the negative electrode material capable of intercalatingand deintercalating lithium ions may be materials other than theabove-described materials. In addition, two or more kinds of thenegative electrode materials may be mixed in an arbitrary combination.

For example, the negative electrode active material layer may be formedby any one of a gas phase method, a liquid phase method, a thermalspraying method, a firing method, and an application method, and two ormore methods of these may be used in combination. In the case of formingthe negative electrode active material layer by using the gas phasemethod, the liquid phase method, the thermal spraying method, the firingmethod, or two or more kinds of methods thereof, it is preferable thatthe negative electrode active material layer and the negative electrodecurrent collector be alloyed at least at a part of an interface.Specifically, it is preferable that in the interface, a constituentelement of the negative electrode current collector diffuse to thenegative electrode active material layer, a constituent element of thenegative electrode active material layer diffuse to the negativeelectrode current collector, or the constituent elements diffuse to eachother. This is because fracture due to expansion and contraction of thenegative electrode active material layer in accordance with charging anddischarging can be suppressed, and electron conductivity between thenegative electrode active material layer and the negative electrodecurrent collector can be improved.

In addition, examples of the gas phase method include a physicaldeposition method and a chemical deposition method, specifically, avacuum deposition method, a sputtering method, an ion plating method, alaser ablation method, a thermochemical vapor deposition (CVD; chemicalvapor deposition) method, a plasma chemical vapor deposition method, andthe like. As the liquid phase method, known methods such aselectroplating, electroless plating, and the like may be used. Forexample, the firing method is a method in which a particle-shapednegative electrode active material is mixed with a binding agent and thelike, the resultant mixture is dispersed in a solvent, the resultantdispersed solution is applied, and a heat treatment is performed at atemperature higher than the melting point of the binding agent and thelike. With regard to the firing method, a known method can be used, andexamples thereof include an atmosphere firing method, a reaction firingmethod, and a hot press firing method.

Separator

The separator is a component that isolates the positive electrode andthe negative electrode from each other to prevent short-circuiting dueto mutual contact of the electrodes, and allows lithium ions to passtherethrough. The separator is constituted by, for example, a porousmembrane formed from a synthetic resin such as polytetrafluoroethylene,polypropylene, and polyethylene, or a porous membrane formed fromceramic, and may have a structure in which two or more kinds of theporous membranes are laminated.

Electrolyte

The electrolyte includes a polymer compound, and a nonaqueouselectrolytic solution (electrolytic solution) that includes a solventand an electrolyte salt. For example, the electrolyte includes agel-shape electrolyte in which the nonaqueous electrolytic solution isretained by the polymer compound. For example, the polymer compound isimpregnated with the electrolytic solution, and thus the polymercompound swells and forms a so-called gel shape. In the electrolyte, forexample, the gel-shaped polymer compound itself, which absorbs andretains the electrolytic solution, functions as an ion conductor.

Nonaqueous Electrolytic Solution

The nonaqueous electrolytic solution includes an electrolyte salt and anonaqueous solvent that dissolves the electrolyte salt.

Electrolyte Salt

For example, the electrolyte salt contains one or more kinds of lightmetal compounds such as a lithium salt. Examples of the lithium saltinclude lithium hexafluorophosphate (LiPF₆), lithium tetrafluoroborate(LiBF₄), lithium perchlorate (LiClO₄), lithium hexafluoroarsenate(LiAsF₆), lithium tetraphenylborate (LiB(C₆H₅)₄), lithiummethanesulfonate (LiCH₃SO₃), lithium trifluoromethane sulfonate(LiCF₃SO₃), lithium tetrachloroaluminate (LiAlCl₄), dilithiumhexafluorosilicate (Li₂SiF₆), lithium chloride (LiCl), lithium bromide(LiBr), and the like. Among these, at least one selected from the groupincluding lithium hexafluorophosphate, lithium tetrafluoroborate,lithium perchlorate, and lithium hexafluoroarsenate is preferable, andlithium hexafluorophosphate is more preferable.

Examples of the nonaqueous solvent include lactone-based solvents suchas γ-butyrolactone, γ-valerolactone, δ-valerolactone, andε-caprolactone, carbonic acid ester-based solvents such as ethylenecarbonate, propylene carbonate, butylene carbonate, vinylene carbonate,dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate,ether-based solvents such as 1,2-dimethoxyethane,1-ethoxy-2-methoxyethane, 1,2-diethoxyethane, tetrahydrofuran,2-methyltetrahydrofuran, nitrile-based solvents such as acetonitrile,sulfolane-based solvents, phosphoric acids, phosphoric acid estersolvents, and nonaqueous solvents such as pyrrolidones. Any one kind ofthe nonaqueous solvents may be used alone, or two or more kinds thereofmay be mixed and used.

In addition, as the nonaqueous solvent, it is preferable to use amixture obtained by mixing cyclic carbonic acid ester and chain carbonicacid ester. It is more preferable to include a compound in which a partor the entirety of hydrogen in cyclic carbonic acid ester and chaincarbonic acid ester is fluorinated. As the fluorinated compound, it ispreferable to use fluoroethylene carbonate(4-fluoro-1,3-dioxolane-2-one: FEC) or difluoro ethylene carbonate(4,5-difluoro-1,3-dioxolane-2-one: DFEC). Among these, it is preferableto use difluoro ethylene carbonate as the nonaqueous solvent. This isbecause an effect of improving cycle characteristics is excellent.

Polymer Compound

As the polymer compound that retains the nonaqueous electrolyticsolution, a polymer that absorbs the nonaqueous electrolytic solutionand gelates, and the like may be used. Examples of the polymer compoundinclude fluorine-based polymer compounds such as a copolymer includingpolyvinylidene fluoride (PVdF) or vinylidene fluoride (VdF), andhexafluoropropylene (HFP) as a repetitive unit, ether-based polymercompounds such as a cross-linked body including polyethylene oxide(PEO), a polymer compound including polyacrylonitrile (PAN),polypropylene oxide (PPO), or polymethyl methacrylate (PMMA) as arepetitive unit, and the like. Any one kind of the polymer compounds maybe used alone, or two or more kinds thereof may be mixed and used.

Particularly, the fluorine-based polymer compounds are preferable fromthe viewpoint of oxidation and reduction stability, and among these, acopolymer including vinylidene fluoride and hexafluoropropylene as acomponent is preferable. In addition, the copolymer may includemonoester of unsaturated dibasic acid such as maleic acid monomethylester (MMM), halogenated ethylene such as trifluorochloroethylene(PCTFE), cyclic carbonic acid ester of an unsaturated compound such asvinylene carbonate (VC), epoxy group-containing acrylic vinyl monomer,or the like as a component. This is because even better characteristicsmay be obtained.

Exterior Material

For example, the exterior material 27 includes a laminated film in whicha resin layer is formed on both surfaces of a metal layer. With regardto the laminated film, an outer resin layer is formed on a surface,which is exposed to the outside of the battery, in the metal layers, andan inner resin layer is formed on a battery inner surface that faces thebattery element 20.

The metal layer plays an important role of blocking penetration ofmoisture, oxygen, and light to protect the content, and as the metallayer, aluminum (Al) is frequently used from the viewpoints oflightness, extensibility, price, and easy processing. The outer resinlayer has beautiful external appearance, toughness, flexibility, and thelike, and as the outer resin layer, a resin material such as nylon andpolyethylene terephthalate (PET) is used. The inner resin layer is aportion which is melted with heat or ultrasonic waves and of which partsare fused to each other, and thus a polyolefin resin is preferable, andnon-stretched polypropylene (CPP) is frequently used. An adhesive layermay be provided between the metal layer and the outer resin layer andbetween the metal layer and the inner resin layer as necessary.

The exterior material 27 is provided with a concave accommodationportion 26 which is formed from the inner resin layer side toward anouter resin layer direction, for example, by deep drawing and whichaccommodates the battery element 20, and the inner resin layer isarranged to face the battery element 20. Parts of the inner resin layer,which is opposite to the exterior material 27, come into close contactwith each other at an outer peripheral portion of the accommodationportion 26 by fusion and the like. The adhesive films 24 and 25, whichare configured to improve adhesiveness between the inner resin layer ofthe exterior material 27 and the leads 21 a and 21 b formed from a metalmaterial, are disposed between the exterior material 27 and the leads 21a and 21 b. The adhesive films 24 and 25 are formed from a resinmaterial having high adhesiveness with the metal material, and areconfigured by a polyolefin resin such as polyethylene, polypropylene,and modified polyethylene or modified polypropylene thereof

In addition, the exterior material 27 may be constituted by a laminatedfilm having a different lamination structure, a polymer film such aspolypropylene, or a metal film instead of the aluminum laminated film inwhich the metal layer is formed from aluminum (Al).

Substrate Section

The substrate section 13 is provided to perform control of an operationof the battery pack, and the like. For example, the substrate section 13is a member that includes a rigid substrate 13 a and a flexiblesubstrate 13 b that is bonded to the rigid substrate 13 a, and the like.A protection circuit (PCM: Protection Circuit Module) is formed in thesubstrate section 13. For example, the substrate section 13 includes acontrol unit, a temperature detection unit, a positive temperaturecoefficient (PTC), a connector for connection with the outside, and thelike.

The control unit controls the overall operation of the battery pack, andincludes, for example, a central processing unit (CPU), a memory, andthe like. The control unit monitors the voltage of the battery cell 11,and in a case where the voltage exceeds a predetermined voltage (forexample, 4.3 V to 4.4 V, and the like), turns off a charging anddischarging control FET so as to prohibit charging. In addition, in acase where the terminal voltage of the battery cell 11 is overdischargedto less than a discharging prohibition voltage and thus the terminalvoltage of the battery cell 11 becomes less than the dischargingprohibition voltage, the control unit turns off the charging anddischarging control FET to prohibit discharging.

The temperature detection unit measures a temperature of the batterycell 11 and outputs a measurement result to the control unit, andincludes, for example, a temperature detection element such as athermistor. In addition, the measurement result obtained by thetemperature detection unit is used in a case where the control unitperforms charging and discharging control at the time of abnormal heatgeneration, in a case where the control unit performs a correctionprocess at the time of calculating remaining capacity, and the like.

In a case where the battery cell 11 reaches a high temperature, the PTCcuts off a current circuit of the battery cell 11 to prevent overheatingof the battery cell 11. The PTC is connected to the battery cell 11 inseries. In a case where a temperature of the battery cell 11 becomeshigher than a temperature that is set, electrical resistance rapidlyincreases, and thus the PTC substantially cuts off a current that flowsto the battery cell 11.

Resin Section

The resin section 12 comes into close contact with a close contactportion that includes at least a part of the battery cell 11, or a closecontact portion that includes at least a part of the battery cell 11 andat least a part of the substrate section 13. The resin section 12 is acured member of a curable resin composition sheet 12′, and includes acured material of the curable resin composition sheet 12′.

Curable Resin Composition Sheet

As the curable resin composition sheet 12′, a thermosetting resincomposition sheet is used. The thermosetting resin composition sheet maybe shape-processed. In addition, the thermosetting resin compositionsheet represents a member that is obtained by molding a thermosettingresin composition into a sheet shape. The sheet shape represents, forexample, a planar shape that is very thin in comparison to the lengthand the width thereof. Typically, a shape having a thickness of 0.2 mmor more is referred to as a sheet shape, and a shape having a thicknessof less than 0.2 mm is referred to as a film shape. However, in thisspecification, both of the shapes are collectively referred to as thesheet shape. The thermosetting resin composition sheet that isshape-processed represents a member obtained by processing thethermosetting resin composition sheet into a desired shape by subjectingthe thermosetting resin composition sheet to, for example, processingsuch as folding and cutting. In the case of using the thermosettingresin composition sheet that is shape-processed, it is preferable thatthe thermosetting resin composition sheet be processed into a shapeconforming to the shape of the close contact portion so as to improveadhesiveness with respect to the close contact portion after curing.

The curable resin composition sheet 12 a′ and the curable resincomposition sheet 12 b′ which are separate from each other adhere to theclose contact portion of the battery cell 11, and then curing isperformed to form the resin section 12 a and the resin section 12 bwhich are separate from each other.

The curable resin composition sheet 12 b′ adheres to one side endsurface 22 b 1, the other side end surface 22 b 2, and a lower endsurface 22 c of the battery cell 11 which constitute the close contactportion. The curable resin composition sheet 12 b′ is a member that isprocessed into a shape conforming to the shapes of the one side endsurface 22 b 1, the other side end surface 22 b 2, and the lower endsurface 22 c of the battery cell 11 which constitute the close contactportion.

For example, the curable resin composition sheet 12 b′ is processed asfollows. A curable resin composition sheet processed into a strip shapeis bent approximately perpendicularly at two sites to have anapproximately U-shaped planar shape, and surface shapes with respect tothe respective end surfaces of the one side end surface 22 b 1, theother side end surface 22 b 2, and the lower end surface 22 c areprocessed to conform to shapes of the respective opposite end surfaces.

The curable resin composition sheet 12 a′ adheres to a part (a portionother than a portion mounted on a terrace portion 22 a) of the rigidsubstrate 13 a and a part of the terrace portion 22 a at the peripheryof the rigid substrate 13 a which constitute the close contact portion.In addition, the terrace portion 22 a is a bonding portion of theexterior material 27 (which includes a portion at which the leads 21 aand 21 b are interposed between parts of the exterior material 27) alongone side on a side at which the leads 21 a and 21 b are provided.

The curable resin composition sheet 12 a′ is processed into a shapeconforming to the close contact portion. For example, the curable resincomposition sheet 12 a′ is a member obtained by processing the curableresin composition sheet into a box shape having an opening in onesurface. The rigid substrate 13 a is put into an inner space of thecurable resin composition sheet 12 a′ processed into a box shape fromthe opening formed in the one surface, and the curable resin compositionsheet 12 a′ adheres to a portion of the rigid substrate 13 a other thana portion mounted on the terrace portion 22 a, and a part of the terraceportion 22 a.

Thermosetting Resin Composition

As the thermosetting resin composition that is used for thethermosetting resin composition sheet, a thermosetting resin compositionthat has been suggested already may be used. Typically, as thethermosetting resin composition, for example, thermosetting resincompositions that contain an epoxy resin, and the like may be used. Thethermosetting resin composition may contain at least any one of anorganic filler, an inorganic filler, a curing agent, and the like inaddition to a resin component.

The thermosetting resin composition sheet may contain a fibrous materialsuch as glass fiber. In this case, it is possible to suppress occurrenceof partial unevenness due to surface tension when the thermosettingresin composition is cured, and thus this case is preferable. Inaddition, it is possible to suppress occurrence of sagging in a resindue to gravity when the thermosetting resin composition is softened, andthus this case is also preferable.

It is preferable that the thermosetting resin composition sheet have thefollowing characteristics. Specifically, the thermosetting resincomposition sheet has, for example, tackiness. In the case of beingheated, the thermosetting resin composition sheet is melted at aninitial heating stage and shows a behavior close to that of a liquidphase, and is cured at a temperature equal to or higher than a curingtemperature and the shape is retained. This is because at the initialheating stage, flowability is improved and thus adhesiveness withrespect to a close contact surface can be improved, and after beingcured, stable hardness can be maintained in a shape that comes intocontact with the close contact surface. In addition, it is easy for aperson having ordinary skill in the art to obtain the thermosettingresin composition sheet having such characteristics. That is, a personhaving ordinary skill in the art can obtain the thermosetting resincomposition sheet having the above-described characteristics byappropriately preparing a composition sheet of the thermosetting resincomposition. In addition, a commercially available thermosetting resincomposition sheet having such characteristics may be used.

Preferred Embodiment of Resin Section

FIGS. 4A and 4B are partial cross-sectional views illustrating a part ofthe resin section which comes into close contact with one side endsurface of the battery cell. As illustrated in FIGS. 4A and 4B, thebattery cell 11 includes a cell main body 11 a including the batteryelement and a part of the exterior material that covers the batteryelement, and a fusion portion 11 b obtained by fusing parts of theexterior material, which face each other, to each other. The fusionportion 11 b is folded back, and at least a part thereof comes intoclose contact with a part of the cell main body 11 a.

It is preferable that the resin section 12 b include a surplus portionthat, when initially formed, does not come into close contact with thefusion portion 11 b that is folded back (as shown in FIG. 5), and thenthe surplus portion is further formed to come into close contact withthe fusion portion 11 b, which is folded back, to a part of the cellmain body 11 a (as shown in FIG. 4A or 4B). This is because it ispossible to more reliably fix the fusion portion 11 b that is foldedback, and it is possible to further improve the strength of the batterypack. In addition, it is preferable that the resin section 12 b beformed not to exceed the highest position of the cell main body 11 a ina thickness direction. This is because it is possible to further improvea volume energy density.

Height of Curable Resin Composition Sheet

FIG. 5 is a partial cross-sectional view illustrating a part of thecurable resin composition sheet that adheres to one side end surface ofthe battery cell. FIG. 5 illustrates a part of the curable resincomposition sheet that has the shape of the resin section before curing.In the curable resin composition sheet 12 b′, the height of an adhesionportion, which adheres to the one side end surface 22 b 1, the otherside end surface 22 b 2, and the lower end surface 22 c which connecttwo opposite main surfaces of the battery cell 11, along a thicknessdirection of the battery cell 11 is preferably defined as follows.

Specifically, it is preferable that the thickness (A) of the cell mainbody and the height (D) of the curable resin composition sheet satisfythe relationship of A≧D. In this case, the resin section 12 b, which isformed when the curable resin composition sheet 12 b′ is cured, isallowed not to exceed the highest position of the cell main body 11 a inthe thickness direction, and as a result, it is possible to furtherimprove the volume energy density.

In addition, it is preferable that the height (D) of the curable resincomposition sheet and the height (B) of the fusion portion that isfolded back satisfy the relationship of D>B. According to this, at leasta part of the surplus portion, which corresponds to a length C (C>0), ofthe curable resin composition sheet 12 b′ comes into close contact witha part of the cell main body 11 a after curing. In addition, the height(B) of the fusion portion 11 b that is folded back represents the lengthup to the highest position of the fusion portion 11 b that is foldedback on the basis of the lowest position of the cell main body 11 a.

In the battery cell 11 that satisfies the relationship of D>B, at leasta part of the resin section 12 b comes into close contact with from thefusion portion 11 b, which is folded back, to a part of the cell mainbody 11 a. As a result, it is possible to more reliably fix the fusionportion 11 b that is folded back, and it is possible to further improvethe strength of the battery pack.

It is preferable that the thickness (A) of the cell main body, theheight (D) of the curable resin composition sheet, and the height (B) ofthe fusion portion that is folded back satisfy the relationships of A≧Dand D>B. According to this, it is possible to allow at least a part ofthe resin section 12 b to come into close contact with from the fusionportion 11 b, which is folded back, to a part of the cell main body 11a, and it is possible to allow the resin section 12 b not to exceed thehighest position of the cell main body 11 a in the thickness direction.As a result, it is possible to more reliably fix the fusion portion 11 bthat is folded back, it is possible to further improve the strength ofthe battery pack, and it is possible to further improve the volumeenergy density.

Method of Manufacturing Battery Pack

A method of manufacturing the battery pack according to the firstembodiment of the present disclosure will now be described.

Process of Preparing Battery Element

First, for example, a positive electrode and a negative electrode inwhich an electrolyte is formed on both surfaces thereof, respectively,and a separator are sequentially laminated in the order of the negativeelectrode, the separator, the positive electrode, and the separator.Then, the laminated body is wound around a flat plate core, and then theresultant body is wound a plurality of times in a longitudinal directionto prepare the wound-type battery element 20.

Process of Preparing Battery Cell

The battery element 20 is accommodated in the accommodation portion 26provided for the exterior material 27, and the exterior material 27 isfolded back to cover the opening of the accommodation portion 26. Then,three sides except a side that is folded back are sealed by thermalfusion and the like to prepare the battery cell 11. At this time, theadhesive films 24 and 25 are interposed between the lead 21 a and theexterior material 27 and between the lead 21 b and the exterior material27, respectively.

Process of Connecting Lead and the Like

The leads 21 a and 21 b of the battery cell 11 are connected to thesubstrate section 13, for example, by thermal welding, ultrasonicwelding, and the like.

Process of Shape-Processing Curable Resin Composition Sheet

Next, as illustrated in FIG. 1, the curable resin composition sheet isprocessed into a shape conforming to the close contact portion so as tomatch the close contact portion. According to this, the curable resincomposition sheet 12 a′ and the curable resin composition sheet 12 b′,which are shape-processed, are obtained. For example, the curable resincomposition sheet is processed into a box shape having an opening in onesurface, thereby obtaining the curable resin composition sheet 12 a′.The curable resin composition sheet is processed into a strip shape, isbent to have an approximate U shape, and is processed into a shapeconforming to the shape of the close contact portion including the oneside end surface 22 b 1, the other side end surface 22 b 2, and thelower end surface 22 c of the battery cell 11, thereby obtaining thecurable resin composition sheet 12 b′.

Process of Forming Resin Section

Next, the rigid substrate 13 a of the substrate section 13 is disposedon the terrace portion 22 a of the battery cell 11, and the curableresin composition sheet 12 a′, which is processed into the box shapehaving the opening in one surface, adheres to a part of the rigidsubstrate 13 a and a part of the terrace portion 22 a at the peripheryof the rigid substrate 13 a, which constitute a close contact portion,as temporary adhesion. Similarly, the curable resin composition sheet 12b′, which is processed into an approximate U shape, adheres to the oneside end surface 22 b 1, the other side end surface 22 b 2, and thelower end surface 22 c of the battery cell 11 which constitute a closecontact portion as temporary adhesion.

Next, the curable resin composition sheets 12 a′ and 12 b′ are heated toa temperature higher than a curing temperature. According to this, thecurable resin composition sheets 12 a′ and 12 b′, which are formed fromthe thermosetting resin composition, are melted at an initial heatingstage, and flowability is improved, and thus adhesiveness with respectto the close contact surface increases. Then, the curable resincomposition sheets 12 a′ and 12 b′ are cured at a temperature equal toor higher than the curing temperature, thereby obtaining the resinsections 12 a and 12 b. According to this, the battery pack according tothe first embodiment of the present disclosure is obtained.

In addition, Shore hardness and Vickers hardness of the resin sections12 a and 12 b can be adjusted by adjusting at least any one of a heatingtemperature and a heating time. According to the hardness adjustment,the resin section 12 after curing can have a state corresponding tohardness according to usage. For example, the resin section 12 aftercuring can be allowed to have a shape having cushioning characteristicswithout hardness. It is possible to design the resin section 12 byselecting a flexible state or a state corresponding to the hardnessaccording to the specifications.

Effect of Battery Pack

Hereinafter, an effect of the battery pack according to this embodimentof the present disclosure will be described by comparison with a typicalbattery pack.

Typical Battery Pack

FIG. 6 is an exploded perspective view of a typical battery pack towhich a frame is applied as an accommodation member of a battery cell.First, a configuration of the battery pack will be briefly described. Asillustrated in FIG. 6, the battery pack includes a label 101, a top tape102, a frame 103, a battery cell 104, an insulating plate 105, a PI(polyimide) tape 106, a substrate section 107 in which a protectivecircuit (PCM) is formed, and an insulating tape 108.

The battery cell 104 is fitted into the frame 103 having a rectangularframe shape. The top tape 102 and the label 101 adhere to the topsurface of the battery cell 104 which is exposed from the frame 103, andthe frame 103, and thus the battery cell 104 is fixed to the frame 103.

The insulating plate 105 and the substrate section 107 are disposed at aterrace portion on a top side of the battery cell 104. The insulatingplate 105 is fixed to the terrace portion of the battery cell 104 by thePI tape 106, and the substrate section 107 is fixed to the terraceportion of the battery cell 104 by the insulating tape 108. Leads 111 aand 111 b, which are led out from the battery cell 104, are connected tothe substrate section 107.

Comparison between Battery Pack According to Embodiment of PresentDisclosure and Typical Battery Pack

FIG. 7A is a perspective view of the battery pack to which the frame isapplied as the accommodation member of the battery cell. FIG. 7B is aperspective view of the battery pack to which the thermosetting resincomposition sheet according to this embodiment of the present disclosureis applied. However, in FIGS. 7A and 7B, a part of the battery pack isomitted. In FIGS. 7A and 7B, a cut-out surface of an omitted portion ofthe battery cell is indicated by diagonal lines. In addition, comparisonis performed on the assumption that external dimensions of the twobattery packs are set to be the same as each other.

FIG. 8A is a cross-sectional view illustrating a region surrounded bydotted lines when viewed from a direction indicated by an arrow VIIIA inthe battery pack shown in FIG. 7A. FIG. 8B is a cross-sectional viewillustrating a region surrounded by dotted lines when viewed from adirection indicated by an arrow VIIIB. FIG. 9A is a cross-sectional viewillustrating a region surrounded by dotted lines when viewed from adirection indicated by an arrow Q1. FIG. 9B is a cross-sectional viewillustrating a region surrounded dotted lines when viewed from adirection indicated by an arrow Q2.

According to the comparison illustrated in FIGS. 8A and 8B, in thebattery pack illustrated in FIG. 8B according to the embodiment of thepresent disclosure, it can be seen that it is possible to increase aportion (battery cell portion), which contributes to battery capacity,on a lower end surface side by a thickness d1 in comparison to thetypical battery pack illustrated in FIG. 8A. According to the comparisonillustrated in FIGS. 9A and 9B, in the battery pack illustrated in FIG.9B according to the embodiment of the present disclosure, it can be seenthat it is possible to increase a portion (battery cell portion), whichcontributes to battery capacity, by a thickness d2 in comparison to thetypical battery pack illustrated in FIG. 9A. In addition, in the batterypack to which a frame is applied, a clearance is apt to occur betweenthe battery cell 104 and the frame 103. However, in the battery pack towhich the thermosetting resin composition sheet according to theembodiment of the present disclosure is applied, the resin section 12 bcomes into close contact with the battery cell 11, and thus it ispossible to avoid capacity loss corresponding to the clearance. Asdescribed above, in the battery pack according to the embodiment of thepresent disclosure, it can be seen that it is possible to improve theenergy density per volume.

Comparison between Battery Pack According to Embodiment of PresentDisclosure and Battery Pack Using Tape

FIG. 10 is an exploded perspective view of a battery pack using tape.First, a configuration of the battery pack will be briefly described. Asillustrated in FIG. 10, the battery pack includes a protective tape 201,a battery cell 202, an insulating tape 203, a holder 204, a substratesection 205 in which a protective circuit (PCM) is formed, and a PI tape206.

The protective tape 201 is a tape material such as a polyimide tape thatis processed into a frame shape having a rectangular contour portion.The protective tape 201 adheres to the battery cell 202 in such a mannerthat a part of the battery cell 202 is exposed from the contour portion,and one side end surface, the other side end surface, a lower endsurface, and a terrace portion of the battery cell 202 are covered withthe frame portion. The insulating tape 203, the substrate section 205,and the holder 204 that covers the substrate section 205 are disposed atthe terrace portion on a top side of the battery cell 202. Theinsulating tape 203, the substrate section 205, and the holder 204 thatcovers the substrate section 205 are fixed by the protective tape 201and the PI tape 206. Leads 211 a and 211 b, which are led out from thebattery cell 202, are connected to the substrate section 205.

FIG. 11A is a cross-sectional view of the battery pack using tape. FIG.11B is a cross-sectional view of the battery pack to which thethermosetting resin composition sheet according to the embodiment of thepresent disclosure is applied. In addition, comparison is performed onthe assumption that external dimensions of the two battery packs are setto be the same as each other.

In the battery pack illustrated in FIG. 11A, a total of three sheets ofprotective tapes 201 overlap each other in a thickness direction of thebattery cell 202. In contrast, in the battery pack according to theembodiment of the present disclosure as illustrated in FIG. 11B, theresin section 12 b, that overlaps the battery cell 202 in a thicknessdirection thereof, can be omitted or reduced. According to this, in thebattery pack according to the embodiment of the present disclosure asillustrated in FIG. 11B, it is possible to reduce the thickness by athickness corresponding to three sheets of tape in comparison to thebattery pack illustrated in FIG. 11A, and thus it can be seen that it ispossible to increase a portion contributing to the battery capacity bythe reduced thickness.

Modification Example 1

The battery pack according to the first embodiment of the presentdisclosure may have the configuration illustrated in FIG. 12. Thebattery pack is the same as that illustrated in FIG. 1 except that twocurable resin composition sheets 12 b 1′ and 12 b 2′, which are separatefrom each other, are used instead of the curable resin composition sheet12 b′ which comes into close contact with the one side end surface 22 b1, the other side end surface 22 b 2, and the lower end surface 22 c. Asillustrated in FIG. 12, the two curable resin composition sheets 12 b 1′and 12 b 2′, which are separate from each other, adhere to two cornerson both side-end sides of the lower end surface 22 c of the battery cell11, respectively. Then, the curable resin composition sheet 12 b 1′ isheated, and thus a resin section that is a cured material of the curableresin composition sheet 12 b 1′ is formed. The resin section comes intoclose contact with one of the two corners on both side-end sides of thelower end surface 22 c that is a close contact portion. Similarly, thecurable resin composition sheet 12 b 2′ is heated, and thus a resinsection that is a cured material of the curable resin composition sheet12 b 2′ is formed. The resin section comes into close contact with theother of the two corners on both side-end sides of the lower end surface22 c that is a close contact portion.

The curable resin composition sheet 12 b 1′ is obtained by processingthe thermosetting resin composition sheet into a shape conforming to onecorner of the battery cell 11 which is a close contact portion. Forexample, the curable resin composition sheet 12 b 1′ is processed asfollows. A thermosetting resin composition sheet processed into a stripshape is bent to have an L shape, and the resultant thermosetting resincomposition sheet is processed into a shape conforming to one corner ofthe battery cell 11 which is a close contact portion.

The curable resin composition sheet 12 b 2′ is obtained by processingthe thermosetting resin composition sheet into a shape conforming to theother corner of the battery cell 11 which is a close contact portion.For example, the curable resin composition sheet 12 b 1′ is processed asfollows. A thermosetting resin composition sheet processed into a stripshape is bent to have an L shape, and the resultant thermosetting resincomposition sheet is processed into a shape conforming to another cornerof the battery cell 11 which is a close contact portion.

Modification Example 2

The battery pack according to the first embodiment of the presentdisclosure may use a laminated sheet as the curable resin compositionsheet 12′. The laminated sheet has a lamination structure includinganother layer that is laminated together with the thermosetting resincomposition sheet. For example, the laminated sheet includes at least acurable resin composition layer, and has a lamination structureincluding the curable resin composition layer constituted by one or morecurable resin composition sheets and one or more different layers. Thelaminated sheet adheres to a close contact portion in such a manner thatthe curable resin composition layer faces the close contact portion.

In the case of using the laminated sheet, it is possible to suppress theoccurrence of partial unevenness due to surface tension during curingand the occurrence of sagging in a resin due to gravity when the resinis softened. Examples of the different layers include a fiber-shapedsheet including a fibrous material such as glass fiber. In addition, asthe different layers, a resin layer such as polyimide, and the like maybe used. In this case, the curable resin composition layer hasadhesiveness, and thus contamination such as a finger print tends tooccur. However, when the resin layer such as polyimide is disposed atthe outermost layer, the resin layer functions as a protective layerthat protects the curable resin composition layer, and thus it ispossible to solve a problem on external appearance such as easyoccurrence of contamination, and thus this disposition is preferable.

Examples of the laminated sheet including at least the curable resincomposition layer include a laminated sheet having a three-layerlamination structure in which the curable resin composition layer, thefiber-shaped sheet layer, and the curable resin composition layer aresequentially laminated in this order, a laminated sheet having atwo-layer lamination structure in which the curable resin compositionlayer and the polyimide (resin layer) are sequentially laminated in thisorder, and the like. In addition, the lamination structure is notlimited to the above-described structure.

Modification Example 3

The battery pack according to the first embodiment of the presentdisclosure may include a curved battery cell. The battery pack can bedisposed in an electronic apparatus such as a wearable terminal, whichcan be attached to a user, along a curved surface of the electronicapparatus, and thus the battery pack is appropriately used as a powersupply of the electronic apparatus.

FIGS. 13A and 13B are exploded perspective views illustrating aconfiguration example of a battery pack according to ModificationExample 3. FIGS. 14A and 14B are perspective views illustrating theexternal appearance of the battery pack of Modification Example 3. Inaddition, in FIGS. 13A and 13B, a curable resin composition sheet, whichhas a state before curing of the resin section illustrated in FIGS. 14Aand 14B, is illustrated.

The battery pack of Modification Example 3 is the same as the batterypack illustrated in FIGS. 1 and 2 except that the shape of the batterycell is different. That is, as illustrated in FIGS. 13A, 13B, 14A, and14B, the battery pack includes a curved battery cell 11, and a resinsection 12 b that comes into close contact with at least a part of thebattery cell 11. In addition, although not illustrated, as is the casewith the battery pack illustrated in FIGS. 1 and 2, the battery packincludes a substrate section 13 that is connected to leads 21 a and 21b, and a resin section 12 a that comes into close contact with a closecontact portion including at least a part of the battery cell 11 and atleast a part of the substrate section 13.

For example, the battery cell 11 has a curved flat shape. The flat shaperepresents a plate shape or an approximate plate shape, and two oppositemain surfaces having a large surface area and surfaces connecting thetwo main surfaces may be a plane or a surface having a curved surface.In addition, a planar shape may be a polygonal shape such as arectangular shape, and a shape such as a circular shape and anelliptical shape which have a curved line. The curved flat shaperepresents a shape including two curved main surfaces. For example, thebattery cell 11 is curved in a thickness direction in such a manner thatboth side ends face a lower side, and the center between the both sideends faces an upper side. Although not illustrated, the battery cell 11may be curved in the thickness direction in such a manner that both ofthe side ends face an upper side, and the center between both of theside ends faces a lower side, may be curved in the thickness directionin such a manner that a front end and a rear end face a lower side, andthe center between the front end and the rear end faces an upper side,or may be curved in the thickness direction in such a manner that thefront end and the rear end face an upper side, and the center betweenthe front end and the rear end faces a lower side. The battery cell 11may be a flexible member in which the degree of flexibility can bechanged.

The curable resin composition sheet 12 b′ adheres to one side endsurface 22 b 1, the other side end surface 22 b 2, and a lower endsurface 22 c of the battery cell 11 having the curved flat shape. Thecurable resin composition sheet 12 b′ is processed into a shapeconforming to the close contact portion of the battery cell having thecurved flat shape. For example, the curable resin composition sheet 12b′ is processed as follows. A curable resin composition sheet processedinto a strip shape is bent approximately perpendicularly at two sites tohave an approximately U-shaped planar shape, and surface shapes withrespect to the respective end surfaces of the one side end surface 22 b1, the other side end surface 22 b 2, and the lower end surface 22 c areprocessed to conform to shapes of the respective opposite end surfaces.In the curable resin composition sheet 12 b′, shape processing is easy,and the curable resin composition sheet 12 b′ can be also appropriatelyused with respect to the battery cell 11 having the curved flat shape.

2. Second Embodiment

A battery pack according to a second embodiment of the presentdisclosure will be described. The battery pack according to the secondembodiment of the present disclosure has the same configuration as thatof the battery pack (also including Modification Examples 1 to 3)according to the first embodiment as illustrated in FIGS. 1 and 2 exceptthat an energy beam curable resin composition sheet is used as thecurable resin composition sheet 12′ instead of the thermosetting resincomposition sheet.

Energy Beam Curable Resin Composition Sheet

The energy beam curable resin composition sheet is obtained by moldingan energy beam curable resin composition into a sheet shape. The energybeam curable resin composition represents a resin composition that canbe cured by irradiation with energy beams. The energy beams representenergy beams such as electron beams, ultraviolet rays, infrared rays,laser beams, visible rays, ionizing radiation (X-rays, α-rays, β-rays,γ-rays, and the like), microwaves, and high-frequency waves which arecapable of causing a polymerization reaction of radicals, cations,anions, and the like. The energy beam curable resin composition may beused as a mixture with a different resin composition as necessary. Forexample, the energy beam curable resin composition may be used as amixture with a curable resin composition such as a thermosetting resincomposition. In addition, two or more kinds of energy beam curable resincompositions may be mixed and used. As the energy beam curable resincomposition, it is preferable to use an ultraviolet curable resincomposition that is cured with ultraviolet rays.

For example, the ultraviolet curable resin composition is composed of amonofunctional monomer, a difunctional monomer, a polyfunctionalmonomer, and the like. Specifically, the ultraviolet curable resincomposition is obtained by using the following materials alone or bymixing a plurality of the following materials. Examples of themonofunctional monomer include carboxylic acids (acrylic acid), hydroxycompounds (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,4-hydroxybutyl acrylate), alkyl, alicyclic compounds (isobutyl acrylate,t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate,isobornyl acrylate, cyclohexyl acrylate), other functional monomers(2-methoxyethyl acrylate, methoxy ethylene glycol acrylate,2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate,ethyl carbitol acrylate, phenoxyethyl acrylate, N,N-dimethylaminoethylacrylate, N,N-dimethylaminopropylacryl amide, N,N-dimethylacrylamide,acryloyl morpholine, N-isopropyl acrylamide, N,N-diethylacrylamide,N-vinyl pyrrolidone, 2-(perfluorooctyl)ethyl acrylate,3-perfluorohexyl-2-hydroxypropyl acrylate,3-perfluorooctyl-2-hydroxypropyl acrylate, 2-(perfluorodecyl)ethylacrylate, 2-(perfluoro-3-methylbutyl)ethyl acrylate),2,4,6-tribromophenol acrylate, 2,4,6-tribromophenol methacrylate,2-(2,4,6-tribromophenoxy)ethyl acrylate), 2-ethylhexyl acrylate, and thelike.

Examples of the difunctional monomer include tri(propyleneglycol)diacrylate, trimethylolpropane diallyl ether, urethane acrylate, and thelike.

Examples of the polyfunctional monomer include trimethylolpropanetriacrylate, dipentaerythritol penta- and hexa-acrylate,ditrimethylolpropane tetraacrylate, and the like.

Examples of initiators include 2,2-dimethoxy-1,2-diphenylethane-1-one,1-hydroxy-cyclohexylphenylketone,2-hydroxy-2-methyl-1-phenylpropane-1-one, and the like.

The energy beam curable resin composition sheet may contain fibrousmaterial such as glass fiber. In this case, it is possible to suppressthe occurrence of partial unevenness due to surface tension when theenergy beam curable resin composition is cured, and thus this case ispreferable. In addition, it is possible to suppress the occurrence ofsagging in a resin due to gravity when the energy beam curable resincomposition is softened, and thus this case is also preferable.

Method of Manufacturing Battery Pack

A method of manufacturing a battery pack according to second embodimentof the present disclosure will be described.

Process of Preparing Battery Element

A process of preparing a battery element is performed in the same manneras in the first embodiment to prepare the battery element 20.

Process of Preparing Battery Cell

Next, a process of preparing a battery cell is performed in the samemanner as in the first embodiment to prepare the battery cell 11.

Process of Connecting Lead and the Like

Next, as is the case with the first embodiment, the leads 21 a and 21 bof the battery cell 11 are connected to the substrate section 13.According to this, components of the battery cell 11 and the substratesection 13 are connected, and thus an integrated assembly is obtained.

Process of Shape-Processing Curable Resin Composition Sheet

Next, as illustrated in FIG. 1, the curable resin composition sheet isprocessed into a shape conforming to the close contact portion so as tomatch the close contact portion. According to this, the curable resincomposition sheet 12 a′ and the curable resin composition sheet 12 b′,which are shape-processed, are obtained. For example, the curable resincomposition sheet is processed into a box shape having an opening in onesurface, thereby obtaining the curable resin composition sheet 12 a′.The curable resin composition sheet is processed into a strip shape, isbent to have an approximate U shape, and is processed into a shapeconforming to a shape of the close contact portion including the oneside end surface 22 b 1, the other side end surface 22 b 2, and thelower end surface 22 c of the battery cell 11, thereby obtaining thecurable resin composition sheet 12 b′.

Process of Forming Resin Section

Next, the rigid substrate 13 a of the substrate section 13 is disposedon the terrace portion 22 a of the battery cell 11, and the curableresin composition sheet 12 a′, which is processed into the box shapehaving the opening in one surface, adheres to a part of the rigidsubstrate 13 a and a part of the terrace portion 22 a at the peripheryof the rigid substrate 13 a as temporary adhesion. Similarly, thecurable resin composition sheet 12 b′, which is processed into anapproximate U shape, adheres to the one side end surface 21 b 1, theother side end surface 21 b 2, and the lower end surface 21 c of thebattery cell 11 which constitute a close contact portion as temporaryadhesion.

Next, the curable resin composition sheets 12 a′ and 12 b′ areirradiated with energy beams such as ultraviolet rays to cure thecurable resin composition sheets 12 a′ and 12 b′. According to this, thecurable resin composition sheets 12 a′ and 12 b′, which are formed fromthe energy beam curable resin composition, are cured, whereby the resinsection 12 a and the resin section 12 b are formed. According to this,the battery pack according to the second embodiment of the presentdisclosure is obtained.

In addition, Shore hardness and Vickers hardness of the resin sections12 a and 12 b can be adjusted by adjusting the irradiation time with theenergy beams such as ultraviolet rays, and the like. According to thehardness adjustment, the resin section 12 after curing can have a statecorresponding to hardness according to usage. For example, the resinsection 12 after curing can be allowed to have a shape havingappropriate cushioning characteristics without hardness. It is possibleto design the resin section 12 by selecting a flexible state or a statecorresponding to hardness according to the specifications.

The battery pack according to the second embodiment has the same effectas in the first embodiment.

3. Third Embodiment

At least any one of the battery packs according to the first and secondembodiments of the present disclosure may be used, for example, to bemounted on an apparatus such as an electronic apparatus, an electricallydriven vehicle, and an electrical storage device, or to supply electricpower thereto.

Examples of the electronic apparatus include a notebook computer, a PDA(portable information terminal), a cellular phone, a cordless phonehandset, a video movie, a digital still camera, an electronic book, anelectronic dictionary, a music player, a radio, a headphone, a gamingmachine, a navigation system, a memory card, a pacemaker, a hearing aid,an electric tool, an electric shaver, a refrigerator, anair-conditioner, a television, a stereo, a water heater, a microwaveoven, a dishwasher, a washing machine, a dryer, an illuminationapparatus, a toy, a medical apparatus, a robot, a road conditioner, asignal apparatus, and the like.

In addition, examples of the electrically driven vehicle include arailway vehicle, a golf cart, an electrically driven cart, an electricvehicle (including a hybrid car), and the like, and the batteries areused as a driving power supply or an auxiliary power supply of thevehicles.

Examples of the electrical storage device include power supplies forelectrical storage of buildings including a house, a power generatingfacility, and the like.

Hereinafter, among the above-described application examples, specificexamples of the electrical storage system using an electrical storagedevice to which the battery pack of the present disclosure is appliedwill be described.

As the electrical storage system, the following configuration may beexemplified. A first electrical storage system is an electrical storagesystem in which an electrical storage device is charged by a powergenerator that performs power generation from renewable energy. A secondelectrical storage system is an electrical storage system that isprovided with an electrical storage device and supplies electric powerto an electronic apparatus that is connected to the electrical storagedevice. A third electrical storage system is an electronic apparatus towhich electric power is supplied from an electrical storage device. Thiselectrical storage system is executed as a system that realizeseffective power supply in cooperation with an external power supplynetwork.

In addition, a fourth electrical storage system is an electricallydriven vehicle provided with a conversion device to which electric poweris supplied from an electrical storage device and which converts theelectric power to a driving force of a vehicle, and a control devicethat performs information processing relating to a vehicle control onthe basis of information relating to the electrical storage device. Afifth electrical storage system is a power system that is provided withan electric power information transmitting and receiving unit thattransmits and receives electric power information to and from otherapparatuses through a network, in which a charge and discharge controlof the above-described electrical storage device is performed on thebasis of the information that is received by the transmitting andreceiving unit. A sixth electrical storage system is a power system towhich electric power is supplied from the above-described electricalstorage device or which supplies electric power from a power generatoror a power network to the electrical storage device. Hereinafter, theelectrical storage system will be described.

(3-1) Electrical Storage System in House as Application Example

An example in which an electrical storage device using the battery packaccording to an embodiment of the present disclosure is applied to anelectrical storage system for a house will be described with referenceto FIG. 15. For example, in an electrical storage system 400 for a house401, electric power is supplied to an electrical storage device 403 froma centralized power system 402 such as a thermal power generation 402 a,a nuclear power generation 402 b, a hydraulic power generation 402 cthrough a power network 409, an information network 412, a smart meter407, a power hub 408, and the like. In addition, electric power from anindependent power supply such as an in-house power generator 404 issupplied to the electrical storage device 403. The electric powersupplied to the electrical storage device 403 is stored. Electric powerthat is used in the house 401 is supplied by using the electricalstorage device 403. The same electrical storage system may also be usedwith respect to a building without limitation to the house 401.

The power generator 404, power-consuming devices 405, the electricalstorage device 403, a control device 410 that controls various devices,the smart meter 407, and sensors 411 that acquire various pieces ofinformation are provided in the house 401. The respective devices areconnected by the power network 409 and the information network 412. Asthe power generator 404, a solar cell, a fuel cell, or the like is used,and generated power is supplied to the power-consuming devices 405and/or the electrical storage device 403. Examples of thepower-consuming devices 405 include a refrigerator 405 a, anair-conditioner 405 b, a television receiver 405 c, a bath 405 d, andthe like. In addition, examples of the power-consuming device 405include an electrically driven vehicle 406. Examples of the electricallydriven vehicle 406 include an electric vehicle 406 a, a hybrid car 406b, and an electric bike 406 c.

The battery pack according to the embodiment of the present disclosureis applied to the electrical storage device 403. The battery cell of thebattery pack according to the embodiment of the present disclosure maybe constituted, for example, by the above-described lithium ionsecondary battery. The smart meter 407 has a function of measuring theamount of commercial power used and of transmitting this measured anamount used to a power company. The power network 409 may be any one ofa DC power supply type, an AC power supply type, and a non-contact powersupply type, or a combination of a plurality of these types.

Examples of the various sensors 411 include a motion sensing sensor, aluminance sensor, an object sensing sensor, a power-consumption sensor,a vibration sensor, a contact sensor, a temperature sensor, an infraredsensor, and the like. Information acquired by the various sensors 411 istransmitted to the control device 410. Weather conditions, conditions ofhuman, or the like is grasped by the information transmitted from thesensors 411, and the power-consuming devices 405 are automaticallycontrolled. Therefore, it is possible to minimize theenergy-consumption. In addition, the control device 410 may transmitinformation related to the house 401 to an external power company or thelike through the Internet.

Processes such as divergence of power lines and DC-AC conversion areperformed by the power hub 408. As a communication method of theinformation network 412 connected to the control device 410, a methodusing a communication interface such as a universal asynchronousreceiver-transceiver (UART: transmission and reception circuit forasynchronous serial communication), and a method using a sensor networkcompliant to a wireless communication standard such as Bluetooth,ZigBee, and Wi-Fi may be exemplified. The Bluetooth method is applied tomultimedia communication and may perform one-to-multi connectioncommunication. ZigBee uses a physical layer defined by the institute ofelectrical and electronics engineers (IEEE) 802.15.4. IEEE 802.15.4 isthe name of a short-range wireless network standard called a personalarea network (PAN) or wireless (W) PAN.

The control device 410 is connected to an external server 413. Theserver 413 may be controlled by any one of the house 401, the powercompany, and a service provider. As information that is transmitted toand received from the server 413, for example, power-consumptioninformation, life pattern information, power rates, weather information,disaster information, and information related to power transactions maybe exemplified. These pieces of information may be transmitted to andreceived from in-house power-consuming devices (for example, televisionreceivers), but may be transmitted to and received from devices (forexample, cellular phones, and the like) outside of the house. Thesepieces of information may be displayed on an apparatus such as atelevision receiver, a cellular phone, a personal digital assistant(PDA), and the like which have a display function.

The control device 410, which controls each unit, includes a centralprocessing unit (CPU), a random access memory (RAM), a read only memory(ROM), and the like, and is accommodated in the electrical storagedevice 403 in this example. The control device 410 is connected to theelectrical storage device 403, the in-house power generator 404, thepower-consuming devices 405, the various sensors 411, and the server 413through the information network 412, and has, for example, a function ofadjusting the amount of commercial power used and the amount of powergeneration. Furthermore, in addition to this function, the controldevice 410 may have a function of performing power transactions in apower market, and the like.

As described above, the generated output of the in-house power generator404 (photovoltaic generation and wind power generation) as well as thatof the centralized power system 402 such as the thermal power generation402 a, the nuclear power generation 402 b, and the hydraulic powergeneration 402 c may be stored in the electrical storage device 403.Therefore, even when the generated output of the in-house powergenerator 404 varies, it is possible to make an amount of power that istransmitted to the outside uniform, or it is possible to controldischarge as much as necessary. For example, a method of use describedbelow may be considered. Specifically, the electric power that isobtained from the photovoltaic generation is stored in the electricalstorage device 403, and inexpensive midnight power is also stored in theelectrical storage device 403 at night, and then the electric power thatis stored in the electrical storage device 403 is discharged to be usedin a period of time at which a rate is expensive in the day time.

In addition, in this example, description has been given to an examplein which the control device 410 is accommodated in the electricalstorage device 403, but the control device 410 may be accommodated inthe smart meter 407, or may be configured independently. Furthermore,the electrical storage system 400 may be used in a plurality of homes inan apartment house as targets, or may be used in a plurality of detachedhouses as targets.

(3-2) Electrical Storage System in Vehicle as Application Example

An example in which the present disclosure is applied to an electricalstorage system for a vehicle will be described with reference to FIG.16. FIG. 16 schematically illustrates a configuration example of ahybrid car that employs a series hybrid system to which the presentdisclosure is applied. The series hybrid system is a vehicle thattravels with a power-driving force converting device by using electricpower generated by a generator moved by an engine, or the electric powerthat is temporarily stored in a battery.

In the hybrid vehicle 500, an engine 501, a generator 502, apower-driving force converting device 503, a driving wheel 504 a, adriving wheel 504 b, a wheel 505 a, a wheel 505 b, a battery 508, avehicle control device 509, various sensors 510, and a charging inlet511 are mounted. As the battery 508, the above-described battery packaccording to the embodiment of the present disclosure is applied.

The hybrid vehicle 500 travels using the power-driving force convertingdevice 503 as a power source. An example of the power-driving forceconverting device 503 is a motor. The power-driving force convertingdevice 503 operates with the electric power of the battery 508, and thetorque of the power-driving force converting device 503 is transferredto the driving wheels 504 a and 504 b. In addition, the power-drivingforce converting device 503 may be applicable to an AC motor or a DCmotor by using DC-AC conversion or invert conversion (AC-DC conversion)as necessary. The various sensors 510 control the engine speed or theopening degree (throttle opening degree) of a throttle valve (notillustrated) through the vehicle control device 509. Examples of thevarious sensors 510 include a speed sensor, an acceleration sensor, anengine speed sensor, and the like.

Torque of the engine 501 may be transferred to the generator 502, andelectric power generated by the generator 502 using the torque may bestored in the battery 508.

When the hybrid vehicle 500 is decelerated with a brake mechanism (notillustrated), a resistance force during the deceleration is added to thepower-driving force converting device 503 as torque, and regeneratedelectric power that is generated by the power-driving force convertingdevice 503 due to the torque is stored in the battery 508.

When the battery 508 is connected to an external power supply outsidethe hybrid vehicle 500, electric power may be supplied to the battery508 from the external power supply by using the charging inlet 511 as aninput inlet and may store the supplied electric power.

Although not illustrated, an information processing device, whichperforms information processing related to vehicle control on the basisof information related to a secondary battery, may be provided. Examplesof the information processing device include an information processingdevice that performs display of the residual amount of the battery onthe basis of information regarding the residual amount of the battery,and the like.

In addition, hereinbefore, description has been given to the serieshybrid car that travels with a motor by using electric power generatedby a generator moved by an engine or the electric power that istemporarily stored in a battery as an example. However, the presentdisclosure may be effectively applied to a parallel hybrid car that usesboth the output of the engine and the output of the motor as drivingsources, and utilizes three types of traveling including traveling usingthe engine only, traveling using the motor only, and traveling using theengine and motor by appropriately changing these types. In addition, thepresent disclosure may be effectively applied with respect to aso-called electrically driven vehicle that travels using driving by adriving motor only without using the engine.

4. Fourth Embodiment

At least one of the battery packs according to the first and secondembodiments may be used as a power supply of a wearable apparatus havinga portable information terminal function, that is, a so-called wearableterminal. Examples of the wearable terminal include a wrist-watch typeterminal, an eyeglass type terminal, and the like, but there is nolimitation thereto.

FIG. 17 illustrates an example of a battery pack-embedded wearableterminal. As illustrated in FIG. 17, a wearable terminal 630 accordingto the fourth embodiment of the present disclosure is a wrist-watch typeterminal, and includes a battery pack 632 inside thereof. The wearableterminal 630 can be used in a state of being attached to a user. Thewearable terminal 630 may be a deformable flexible terminal.

As illustrated in FIG. 18, the wearable terminal 630 according to thefourth embodiment of the present disclosure includes an electroniccircuit 631 of an electronic apparatus main body, and a battery pack632. The battery pack 632 is electrically connected to the electroniccircuit 631. As the battery pack 632, the battery pack according to thefirst embodiment or the second embodiment may be used. For example, thewearable terminal 630 has a configuration in which the battery pack 632is detachable by a user. However, the configuration of the wearableterminal 630 is not limited thereto, and the wearable terminal 630 mayhave a configuration in which the battery pack 632 is embedded insidethe wearable terminal 630 so as not to allow the user to separate thebattery pack 632 from the wearable terminal 630.

During charging of the battery pack 632, a positive electrode terminal634A and a negative electrode terminal 634B of the battery pack 632 areconnected to a positive electrode terminal and a negative electrodeterminal of a charger (not illustrated), respectively. On the otherhand, during discharging of the battery pack 632 (during use of thewearable terminal 630), the positive electrode terminal 634A and thenegative electrode terminal 634B of the battery pack 632 are connectedto a positive electrode terminal and a negative electrode terminal ofthe electronic circuit 631, respectively.

Electronic Circuit

For example, the electronic circuit 631 includes a CPU, a peripherallogic unit, an interface unit, a storage unit, and the like, andcontrols the entirety of the wearable terminal 630.

Battery Pack

The battery pack 632 includes a battery cell 610, and a charging anddischarging circuit 633.

During charging, the charging and discharging circuit 633 controlcharging with respect to the battery cell 610. On the other hand, duringdischarging (that is, during use of the wearable terminal 630), thecharging and discharging circuit 633 controls discharging with respectto the wearable terminal 630.

5. Other Embodiments

Hereinbefore, the respective embodiments of the present disclosure havebeen described, but the present disclosure is not limited thereto, andvarious modifications can be made in the range of the gist of thepresent disclosure.

For example, the numerical values, the structures, the shapes, thematerials, the raw materials, the manufacturing processes, and the like,which are exemplified in the above-described embodiments, areillustrative only, and different dimensions, structures, shapes,materials, raw materials, manufacturing processes, and the like may beused as necessary.

In addition, the configurations, the methods, the processes, the shapes,the materials, the numerical values, and the like in the above-describedembodiments may be combined with each other as long as the combinationdoes not depart from the gist of the present disclosure. For example,the battery cell may a primary battery. For example, only one of theresin sections may be provided, and four or more of the resin sectionsthat are separate from each other may be provided. In addition, amulti-layer curable resin composition sheet, in which single-layercurable resin composition sheets are laminated, may be used.

In addition, the present disclosure may employ the followingconfigurations.

(1) A battery comprising:

a battery cell having main top and bottom surfaces, and a plurality ofside surfaces; and

at least one resin section including a cured resin that covers at leastthree of the plurality of side surfaces of the battery cell, but thatdoes not cover substantially all of the top and bottom surfaces of thebattery cell.

(2) The battery according to (1), wherein the resin section also coversat least one corner of adjacent side surfaces of the battery cell.

(3) The battery according to (1) or (2), wherein the resin sections havea flexible characteristic.

(4) The battery according to any one of (1) to (3), wherein at least oneof the resin sections has a bent shape that conforms to a shape of oneof the side surfaces of the battery cell.

(5) The battery according to any one of (1) to (4), wherein at least oneof the resin sections covers a fourth side of the battery cell, andwherein a substrate section is formed between the resin section and thefourth side of the battery cell.

(6) The battery according to (5), wherein the resin section covering thefourth side of the battery cell has a box shape having an opening in onesurface thereof, the resin section formed around an end of the batterycell.

(7) The battery according to any one of (1) to (6), wherein the resinsections include a fibrous filler material.

(8) The battery according to any one of (1) to (7),

wherein the battery cell includes a cell main body including a batteryelement, and an exterior material that covers the battery element, theresin sections being formed on the exterior material.

(9) The battery according to (8),

wherein the exterior material includes a fusion portion that is foldedback to contact the cell main body.

(10) The battery according to (9), wherein a height (D) of at least oneof the resin sections and a height (B) of the folded back part of thefusion portion satisfy the following relationship D>B.

(11) The battery according to (10), wherein at least part of one of theresin sections contacts and is formed between the folded back part ofthe fusion portion and the cell main body.

(12) The battery according to any one of (1) to (11), wherein a highestpoint of at least one of the resin sections does not exceed a highestpoint of a cell main body of the battery cell in a thickness directionthereof

(13) The battery according to any one of (1) to (12), wherein athickness (A) of a cell main body of the battery cell and a height (D)of at least one of the resin sections satisfy the following relationshipA≧D.

(14) A battery comprising:

a battery cell having main top and bottom surfaces, a plurality of sidesurfaces, and a plurality of corners; and

at least one resin section including a cured resin that covers portionsof at least two corners of the battery cell, but that does not coversubstantially all of the top and bottom surfaces of the battery cell.

(15) The battery according to (14), comprising a plurality of separateresin sections, each resin section covering a different corner of thebattery cell.

(16) The battery according to (14) or (15), wherein at least one of theresin sections covers a side of the battery cell, and wherein asubstrate section is formed between the resin section and the side ofthe battery cell.

(17) The battery according to any one of (14) to (16), wherein the resinsections include a fibrous filler material.

(18) A battery comprising:

a battery cell having a plurality of side surfaces and at least onecurved surface connecting the side surfaces; and

at least one resin section that covers the side surfaces of the batterycell, but that does not cover at least substantially all of the curvedsurface of the battery cell.

(19) The battery according to (18), wherein the resin sections have aflexible characteristic.

(20) The battery according to (18) or (19), wherein the resin sectionsinclude a fibrous filler material.

(21) The battery according to any one of (18) to (20), wherein thecurved surface is a curved plate shape or an approximate curved plateshape.

(22) An electronic device including the battery of (1).

(23) An electric vehicle including the battery of (1), and furthercomprising:

a conversion device to which electric power is supplied from the batteryand which converts the electric power to a driving force of theelectronic vehicle; and

a control device that performs information processing relating to avehicle control on the basis of information relating to the battery.

(24) An electrical storage device including the battery of (1).

(25) An electrical storage system including the battery of (1), andfurther comprising an electric power information transmitting andreceiving unit that transmits and receives electric power information toand from other apparatuses through a network,

wherein a charge and discharge control of the battery is performed onthe basis of the information that is received by the transmitting andreceiving unit.

(26) A wearable terminal including the battery of claim 1, and furthercomprising an electronic apparatus main body including an electroniccircuit, the electronic circuit being electrically connected to theelectronic circuit.

(27) The wearable terminal according to (26), wherein the battery isremovable from the electronic apparatus main body.

(28) The wearable terminal according to (26) or (27), wherein theelectronic apparatus main body has a curved shape.

(29) The wearable terminal according to any one of (26) to (28), whereinthe electronic apparatus main body has flexible and deformablecharacteristics.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The application is claimed as follows:
 1. A battery comprising: abattery cell having main top and bottom surfaces, and a plurality ofside surfaces; and at least one resin section including a cured resinthat covers at least three of the plurality of side surfaces of thebattery cell, but that does not cover substantially all of the top andbottom surfaces of the battery cell, wherein the battery cell includes acell main body including a battery element, and an exterior materialthat covers the battery element, the resin sections being formed on theexterior material, wherein the exterior material includes a fusionportion that is folded back to contact the cell main body, wherein aheight (D) of at least one of the resin sections and a height (B) of thefolded back part of the fusion portion satisfy the followingrelationship D>B, and. wherein at least part of one of the resinsections contacts and is formed between the folded back part of thefusion portion and the cell main body.
 2. The battery according to claim1, wherein the resin section also covers at least one corner of adjacentside surfaces of the battery cell.
 3. The battery according to claim 1,wherein the resin sections have a flexible characteristic.
 4. Thebattery according to claim 1, wherein at least one of the resin sectionshas a bent shape that conforms to a shape of one of the side surfaces ofthe battery cell.
 5. The battery according to claim 1, wherein at leastone of the resin sections covers a fourth side of the battery cell, andwherein a substrate section is formed between the resin section and thefourth side of the battery cell.
 6. The battery according to claim 5,wherein the resin section covering the fourth side of the battery cellhas a box shape having an opening in one surface thereof, the resinsection formed around an end of the battery cell.
 7. The batteryaccording to claim 1, wherein the resin sections include a fibrousfiller material.
 8. The battery according to claim 1, wherein a highestpoint of at least one of the resin sections does not exceed a highestpoint of a cell main body of the battery cell in a thickness directionthereof.
 9. The battery according to claim 1, wherein a thickness (A) ofa cell main body of the battery cell and a height (D) of at least one ofthe resin sections satisfy the following relationship A≧D.
 10. Anelectronic device including the battery of claim
 1. 11. An electricvehicle including the battery of claim 1, and further comprising: aconversion device to which electric power is supplied from the batteryand which converts the electric power to a driving force of theelectronic vehicle; and a control device that performs informationprocessing relating to a vehicle control on the basis of informationrelating to the battery.
 12. An electrical storage device including thebattery of claim
 1. 13. An electrical storage system including thebattery of claim 1, and further comprising an electric power informationtransmitting and receiving unit that transmits and receives electricpower information to and from other apparatuses through a network,wherein a charge and discharge control of the battery is performed onthe basis of the information that is received by the transmitting andreceiving unit.
 14. A wearable terminal including the battery of claim1, and further comprising an electronic apparatus main body including anelectronic circuit, the electronic circuit being electrically connectedto the electronic circuit.
 15. The wearable terminal according to claim14, wherein the battery is removable from the electronic apparatus mainbody.
 16. The wearable terminal according to claim 14, wherein theelectronic apparatus main body has a curved shape.
 17. The wearableterminal according to claim 14, wherein the electronic apparatus mainbody has flexible and deformable characteristics.
 18. A batterycomprising: a battery cell having main top and bottom surfaces, aplurality of side surfaces, and a plurality of corners; and at least oneresin section including a cured resin that covers portions of at leasttwo corners of the battery cell, but that does not cover substantiallyall of the top and bottom surfaces of the battery cell, wherein thebattery cell includes a cell main body including a battery element, andan exterior material that covers the battery element the resin sectionsbeing formed on the exterior material, wherein the exterior materialincludes a fusion portion that is folded back to contact the cell mainbody, wherein a height (D) of at least one of the resin sections and aheight (B) of the folded back part of the fusion portion satisfy thefollowing relationship D>B, and wherein at least part of one of theresin sections contacts and is formed between the folded back part ofthe fusion portion and the cell main body.
 19. The battery according toclaim 18, comprising a plurality of separate resin sections, each resinsection covering a different corner of the battery cell.
 20. The batteryaccording to claim 18, wherein at least one of the resin sections coversa side of the battery cell, and wherein a substrate section is formedbetween the resin section and the side of the battery cell.
 21. Thebattery according to claim 18, wherein the resin sections include afibrous filler material.
 22. A battery comprising: a battery cell havinga plurality of side surfaces and at least one curved surface connectingthe side surfaces; and at least one resin section that covers the sidesurfaces of the battery cell, but that does not cover at leastsubstantially all of the curved surface of the battery cell, wherein thebattery cell includes a cell main body including a battery element., andan exterior material that covers the battery element, the resin sectionsbeing formed on the exterior material, wherein the exterior materialincludes a fusion portion that is folded back to contact the cell mainbody, wherein a height (D) of at least one of the resin sections and aheight (B) of the folded back art of the fusion portion satisfy thefollowing relationship D>B and wherein at least part of one of the resinsections contacts and is formed between the folded back part of thefusion portion and the cell main body.
 23. The battery according toclaim 22, wherein the resin sections have a flexible characteristic. 24.The battery according to claim 22, wherein the resin sections include afibrous filler material.
 25. The battery according to claim 22, whereinthe curved surface is a curved plate shape or an approximate curvedplate shape.